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Rare Metals 2020年第6期39卷 680-687页

作者： Xia-Xia Li Pei-Yao Zhu Qing Li Yu-Xia Xu Yan Zhao Huan Pang School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou 225009China Guangling College Yangzhou UniversityYangzhou 225000China College of Chemistry and Materials Science Sichuan Normal UniversityChengdu 610068China

Here,N-and P-doped carbon-carbon nanotube CoP(NPC-CNTs-CoP)nanoparticles dodecahedra are achieved by multistep calcination of the Zn-doped zeolitic imidazolate framework ZIF-67 precursor(ZnCo-ZIF).In the structures,the presence of N and P atoms,abundant CNTs and the CoP nanoparticles can enhance electrochemical activity and promote the structural stability of *** the temperature increases,the Zn contents gradually reduce to zero,which provides more active sites for electrochemical ***,the high specific surface area and microporous behavior of NPC-CNTsCoP-9 make it excellent in electrocatalytic ***-CoP-9 shows a low overpotential of 224 mV at10 mA·cm^-2 in 1.0 mol·L^-1 KOH *** strategy of zeolitic imidazole framework-derived transition metal phosphides will provide a new sight for developing energy conversion materials.

关键词： nitrogen Phosphorus Carbon Carbon nanotube CoP Oxygen evolution

nitrogen-cycling microbial community functional potential and enzyme activities in cultured biofilms with response to inorganic nitrogen availability

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Journal of Environmental Sciences 2019年第2期31卷 89-99页

作者： Shuangshuang Li Chengrong Peng Taisheng Cheng Chun Wang Liangliang Guo Dunhai Li Key Laboratory of Algal Biology Institute of HydrobiologyChinese Academy of Sciences Hebei Engineering Research Center for Water Pollution Control and Water Ecological Remediation College of Energy and Environmental EngineeringHebei University of Engineering National University of Tainan Department of Biological Sciences and Technology Environmental Simulation and Pollution Control State Key Joint Laboratory and State Environmental Protection Key Laboratory of Microorganism Application and Risk Control(SMARC) School of EnvironmentTsinghua University

Biofilms mediate crucial biochemical processes in aquatic ecosystems. It was hypothesized that eutrophication may promote the growth of biofilms, resulting in larger numbers of functional genes. However, the metabolic activity and the roles of biofilms in N cycling will be affected by ambient inorganic nitrogen availability, not by the abundance of functional genes. Biofilms were cultured either with replete inorganic nitrogen(N-rep) or without exogenous inorganic nitrogen supply(N-def) in a flow incubator, and the N-cycling gene abundances(nifH, N_2 fixation; amoA, ammonia oxidation, archaea and bacteria; nirS and nirK, denitrification) and enzyme activities(nitrogenase and nitrate reductase) were analyzed. The results showed that, comparing the N-def and N-rep biofilms, the former contained lower nifH gene abundance, but higher nitrogenase activity(NA), while the latter contained higher nifH gene abundance, but lower NA. Different patterns of NA diel variations corresponded to the dynamic microbial community composition and different stages of biofilm colonization. Ammonia oxidizing bacteria(AOB), detected only in N-def biofilms, were responsible for nitrification in biofilms. N-rep biofilms contained high nirS and nirK gene abundance and high denitrification enzyme activity, but N-def biofilms contained significantly lower denitrification gene abundance and activity. In general,the strong N_2 fixation in N-def biofilms and strong denitrification in N-rep biofilms assured the balance of aquatic ecosystems. The results suggested that evaluation of the functional processes of N cycling should not only focus on genetic potential, but also on the physiological activity of biofilms.

关键词： Cultured biofilms nitrogen availability nitrogen-cycling enzymes nitrogen-cycling genes

nitrogen interception in floodwater of rice field in Taihu region of China

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Journal of Environmental Sciences 2007年第12期19卷 1474-1481页

作者： LIANG Xin-qiang CHEN Ying-xu LI Hua TIAN Guang-ming ZHANG Zhi-jian NI Wu-zhong HE Miao-miao Department of Environmental Engineering College of Natural Resources and Environmental Science Zhejiang University Hangzhou 310029 China.

A field experiment located in Taihu Lake Basin of China was conducted, by application of urea or a mixture of urea with manure, to elucidate the interception of nitrogen （N） export in a typical rice field through ＂zero-drainage water management＂ combined with sound irrigation, rainfall forecasting and field drying. N concentrations in floodwater rapidly declined before the first event of field drying after three split fertilizations, and subsequently tended to rearm to the background level. Before the first field drying, total particulate nitrogen （TPN） was the predominant N form in floodwater of plots with no N input, dissolved inorganic nitrogen （DIN） on plots that received urea only, and dissolved organic nitrogen （DON） on plots treated with the mixture of urea and manure. Thereafter TPN became the major form. No N export was found from the rice field, but total nitrogen （TN） of 15.8 kg/hm^2 was remained, mainly due to soil N sorption. The results recommended the zero-drainage water management for full-scale areas for minimizing N export.

关键词： nitrogen paddy field surface floodwater interception Taihu region

nitrogen transformations during pig manure composting

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Journal of Environmental Sciences 2001年第4期13卷 401-405页

作者： HUANG Guo-feng WU Qi-tang LI Fang-bai WONG J.W.C College of Natural Resources and Environment South China Agricultural UniversityWushanGuangzhou 510642 Department of Biology Hong Kong Baptist UniversityKowloonHKSAR

Composting is now suggested as one of the environmentally and friendly alternative method for disposal of solid organic wastes, as it leads to minimization, stabilization, and utilization of organic waste. Transformations of nitrogen were investigated in co-composting of pig manure with different amendments, such as sawdust and leaves. Samples were analyzed for pH, total-N, soluble NH4-N, soluble NO3-N and soluble organic-N. The total-N increased after 63 days of composting, as well as the soluble NO3-N and soluble organic-N. Soluble NH4,-N increased significantly and showed peak values at day 7, thereafter decreased sharply and gradually to lower levels. Seed germination index (GI) showed that co-composting of pig manure with sawdust reached maturity after 49 days of composting, while co-composting of pig manure with sawdust and leases required shorter time for 35 days. Soluble NH4-N was significantly negatively ( P nitrogen transformations, but it was beneficial for maturity of pig manure compost.

关键词： pig manure composting nitrogen transformation maturity

nitrogen deposition and release pattern of slow release fertiliser made from urea-impregnated oil palm frond and rubberwood chips

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Journal of Forestry Research 2019年第6期30卷 2087-2094页

作者： Nur Nabilah Abdul Khalid Zaidon Ashaari Ahmad Husni Mohd.Hanif Azmy Mohamed Seng Hua Lee Department of Forest Production Faculty of ForestryUniversiti Putra Malaysia(UPM)43400 UPM SerdangSelangorMalaysia Institute of Tropical Forestry and Forest Products Universiti Putra Malaysia(UPM)43400 UPM SerdangSelangorMalaysia Department of Land Management Faculty of AgricultureUniversiti Putra Malaysia(UPM)43400 UPM SerdangSelangorMalaysia

The fertiliser industry faces a continuing challenge to improve the efficiency of their products,particularly of nitrogenous fertilisers,and to minimise adverse ***,a new slow release fertilizer,ureaimpregnated woodchips from tropical plant biomass(oil palm frond and rubberwood),was *** morphology of the impregnated woodchips was investigated by scanning electron microscopy and the success of impregnation of urea and nitrogen deposition into the woodchips was confirmed by energy dispersive X-ray *** nitrogen release patterns from impregnated woodchips fertiliser were simulated using a soil solution and distilled water as leaching solutions in a static condition for 768 h,release was slow and steady,although the release rate was lower in distilled water than in the soil solution.

关键词： Woodchips fertilizer Slow-release Urea Release pattern nitrogen deposition

nitrogen Budget in Recirculating Aquaculture and Water Exchange Systems for Culturing Litopenaeus vannamei

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Journal of Ocean University of China 2018年第4期17卷 905-912页

作者： CHEN Zhao GE Hongxing CHANG Zhiqiang SONG Xiefa ZHAO Fazhen LI Jian Fisheries College Ocean University of China Key Laboratory for Sustainable Development of Marine Fisheries Ministry of Agriculture Yellow Sea Fisheries Research Institute Chinese Academy of Fishery Sciences

In order to investigate the culture characteristics of two indoor intensive Litopenaeus vannamei farming modes, recirculating aquaculture system(RAS) and water exchange system(WES), this study was carried out to analyze the water quality and nitrogen budget including various forms of nitrogen, microorganism and chlorophyll-a. nitrogen budget was calculated based on feed input, shrimp harvest, water quality and renewal rate, and collection of bottom mud. Input nitrogen retained in shrimp was 23.58% and 19.10% respectively for WES and RAS, and most of nitrogen waste retained in water and bottom mud. In addition, most of nitrogen in the water of WES was TAN(21.32%) and nitrite(15.30%), while in RAS was nitrate(25.97%), which means that more than 76% of ammonia and nitrite were removed. The effect of microalgae in RAS and WES was negligible. However, bacteria played a great role in the culture system considering the highest cultivable cultivable bacterial populations in RAS and WES were 1.03×10^(10) cfu mL^(-1) and 2.92×10~9 cfu mL^(-1), respectively. Meanwhile the proportion of bacteria in nitrogen budget was 29.61% and 24.61% in RAS and WES, respectively. RAS and WES could realize shrimp high stocking culture with water consuming rate of 1.25 m^3 per kg shrimp and 3.89 m^3 per kg shrimp, and power consuming rates of 3.60 kwh per kg shrimp and 2.51 kwh per kg shrimp, respectively. This study revealed the aquatic environment and nitrogen budget of intensive shrimp farming in detail, which provided the scientific basis for improving the industrial shrimp farming.

关键词： RAS shrimp water quality nitrogen budget microorganism

nitrogen isotopic geochemical characteristics of crude oils in several basins of China

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Science China Earth Sciences 2005年第8期48卷 1211-1219页

作者： CHEN Chuanping1,2, MEI Bowen1 & CAO Yacheng3 1. Jianghan Petroleum University, Jingzhou 434100, China 2. Huazhong University of Science and Technology, Wuhan 430047, China 3. Nanjing Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China 1. Jianghan Petroleum University 434100 Jingzhou China 2. Huazhong University of Science and Technology 430047 Wuhan China 3. Nanjing Institute of Soil Science Chinese Academy of Sciences 210008 Nanjing China

nitrogen isotopic ratios of crude oils with different physical and chemical properties in several basins of China have been measured and their geochemistry has been studied ele-mentally combined with molecular organic geochemistry methods. The data indicate that δ 15N is in the range of ?6‰-20‰. They vary with the oils in different sedimentary types of basins. The oils forming in the limnic environment have lower δ 15N with the value of about 1‰-5‰ whereas the oils in saline or semi-saline environment have higher δ 15N, with most samples being above 10‰ and some exceeding 17‰. The average nitrogen isotopic ratio of oils from the Ordovician formation in the Tarim Basin is the lowest, with most samples having δ 15N below zero, which reflects possibly the characteristic of the oils originating mainly from the organic matter formed in marine carbonate sedimentary environment. The δ 15N distribution can be altered by fractionation. It increases obviously because of biodegradation and decreases during hydrocarbon migration. However, the effect of nitrogen isotopic fractionation in the short distance migration is uncon-spicuous.

关键词： nitrogen isotope, crude oil, sedimentary environment, isotopic fractionation, China.

nitrogen supply affects ion homeostasis by modifying root Casparian strip formation through the miR528-LAC3 module in maize

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Plant Communications 2023年第4期4卷 88-98页

作者： Yu Guo Yafei Wang Huan Chen Qingguo Du Zhonghua Wang Xiaoping Gong Qing Sun Wen-Xue Li National Engineering Laboratory for Crop Molecular Breeding Institute of Crop ScienceChinese Academy of Agricultural SciencesBeijing 100081China Qingdao Agricultural University Qingdao 266109China

Although nitrogen(N)is known to affect mineral element homeostasis in plants,the molecular mechanisms of interactions between N and other nutrients remain largely *** here that N supply affects ion homeostasis *** hemisulfate staining and a propidiumiodide penetration assay showed that N luxury significantly delayed Casparian strip(CS)formation in maize *** further demonstrated that N-mediated CS formation in maize was independent of RBOHF-activated H2O2 production.N luxury induced the expression of ZmmiR528 inwhole roots and root *** and loss-of-function ofZmmiR528 promoted CS formation under both N-luxury and N-deficient *** ZmMIR528a and ZmMIR528b contribute to early CS formation under different N ***-seq and real-time RT-PCR analysis demonstrated that ZmLAC3,but not ZmLAC5,responded to N *** with results obtained with ZmmiR528 TM transgenic maize and mir528a/b loss-of-function mutants,transgenic maize overexpressing ZmLAC3 displayed early CS formation under different N *** field conditions,K,Ca,Mn,Cu,Mg,and Zn concentrations were greater in the ear leaf of ZmLAC3-overexpressing transgenicmaize than in the wild *** results indicate that ZmmiR528 affects CS formation in maize by regulating the expression of ZmLAC3,and modification of CS formation has the potential to improve maize quality.

关键词： nitrogen ion homeostasis miR528 Casparian strip maize

nitrogen application affects maize grain filling by regulating grain water relations

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Journal of Integrative Agriculture 2022年第4期21卷 977-994页

作者： WU Ya-wei ZHAO Bo LI Xiao-long LIU Qin-lin FENG Dong-ju LAN Tian-qiong KONG Fan-lei LI Qiang YUAN Ji-chao College of Agriculture Sichuan Agricultural UniversityChengdu 611130P.R.China Chongqing Key Laboratory of Economic Plant Biotechnology/Collaborative Innovation Center of Special Plant Industry in Chongqing/Institute of Special Plants Chongqing University of Arts and SciencesChongqing 402160P.R.China Crop Ecophysiology and Cultivation Key Laboratory of Sichuan Province Chengdu 611130P.R.China

Grain water relations play an important role in grain filling in maize. The study aimed to gain a clear understanding of the changes in grain dry weight and water relations in maize grains by using hybrids with contrasting nitrogen efficiencies under differing nitrogen levels. The objectives were: 1) to understand the changes in dry matter and percent moisture content(MC) during grain development in response to different nitrogen application rates and 2) to determine whether nitrogen application affects grain filling by regulating grain water relations. Two maize hybrids, high N-efficient Zhenghong 311(ZH311) and low N-efficient Xianyu 508(XY508), were grown in the field under four levels of N fertilizer: 0, 150, 300, and 450 kg N ha;during three growing seasons. Dry weight, percent MC and water content(WC) of basal-middle and apical grains were investigated. The difference in the maximum WC and filling duration of basal-middle and apical grains in maize ears resulted in a significant difference in final grain weight. Grain position markedly influenced grain drying down;specifically, the drying down rate of apical grains was faster than that of basal-middle grains. Genotype and grain position both influenced the impact of nitrogen application rate on grain filling and drying down. nitrogen rate determined the maximum grain WC and percent MC loss rate in the middle and the late grain-filling stages, thus affecting final grain weight. The use of high N-efficient hybrids, combined with the reduction of nitrogen application rate, can coordinate basal-middle and apical grain drying down to ensure yield. This management strategy could lead to a win-win situation in which the maximum maize yield, efficient mechanical harvest and environmental safety are all achieved.

关键词： maize grain filling grain drying down nitrogen maximum water content

nitrogen uptake regime regulated by ice melting during austral summer in the Prydz Bay, Antarctica

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Acta Oceanologica Sinica 2019年第8期38卷 1-7页

作者： Run Zhang Qiang Ma Min Chen Minfang Zheng Jianping Cao Yusheng Qiu College of Ocean and Earth Sciences Xiamen University Xiamen 361102 China Key Laboratory of Estuarine Ecological Security and Enviromental Health Xiamen University Tan Kah Kee College Zhangzhou 363105 China

Using a combination of stable isotope(15N) and radionuclide(226Ra) analyses, we examine possible controls on the interactions between melting ice and the uptake of nitrogen in the Prydz Bay during the 2006 austral *** find that specific rates of uptake for nitrate and ammonium correlate positively to their concentrations, thus suggesting a substrate effect. In the study area, we observe that regions along open, oceanic water have high fratios(nitrate uptake/nitrate+ammonium uptake), while areas near the Amery Ice Shelf have significantly low fratios. Further analysis reveals a negative correlation between the f-ratio and the melt water fraction, thus implying that the melting of ice plays an essential role in regulating pelagic N dynamics in the Southern Ocean(SO). Stratification, produced by melting ice, should profoundly affect the efficiency of the SO’s biological pump and consequently affect the concentration of CO2 in the atmosphere. Results presented in this study add information to an already significant base of understanding of the controls on pelagic C and N dynamics in the SO. This provides unique insights for either interpreting past changes in geologic records or for predicting future climate change trends.

关键词： nitrogen uptake regime ice melting Prydz Bay Antarctica